1. Field
The present invention generally relates to devices for filtration of water entering storm water drainage systems through a roadway curb opening, and in particular to a barrier filter for a curb inlet of a storm water drainage system adapted to filter silt and debris from storm water passing through the curb inlet and into the storm water drainage system.
2. Description of the Related Art
In the construction of streets, highways, residential housing developments, commercial developments, schools, airports and similar other types of construction projects, the road system generally is first marked out and the streets of the development are cleared and graded. Thereafter, the storm water drainage system for the development is constructed, which typically includes the underground drainage pipes, collection basins, culverts, and drop inlets that form the connection between the storm water drainage system and the finished street side curb inlet.
The storm water drainage system connected to the curb inlets must be kept substantially free of silt and sediment during the remaining phases of construction, pursuant federal, state and local clean water regulations and building codes. Keeping silt and sediment out of the collection basins is, however, difficult given additional grading on site wherein silt and sediment tends to remain unstable and easily migrates towards the sides of the street by wind, water and construction activity and consequently into the open curb inlets. If silt and sediment are washed into or otherwise collected within the collection basins and/or other parts of the drainage system, the collection basins can become clogged and it becomes necessary to send workers down into the collection boxes to manually clean out the dirt and/or debris that has been washed or accidentally dropped into the collection basins to comply with clean water regulations. Such cleaning operations are difficult as the pipes are somewhat cramped, making it difficult to maneuver, and there is also the danger of cave-ins or collapses of the silt, sediment, dirt, and etc. that has built up around the sides of the collection basins, creating a significant risk of injury or even death to the workers below, as well as the negative environmental impact and clean water regulation violations from the migrating sediment.
Although the simplest solution to this problem would seem to be to completely seal the curb inlet, this solution is not feasible as storm water must be permitted to drain through the drainage system of the development during construction to permit the ground to dry and to prevent storm water from eroding the work site and carrying soil and debris to adjacent lots, buildings or state waters. The streets and roadways must also be kept clear to prevent a potential traffic hazard from standing water.
In the past, various filter systems for protecting the curb inlets of the storm water drainage system have been utilized. Unfortunately, most of these systems have suffered from various disadvantages, including lack of portability and ineffective anchoring to maintain the filter system in place during heavy flows of storm water. Such systems include weir arrangements constructed of gravel supported by a wire screen and the like; rolled bundles of filter material, such as coir wattle; arrangements of cinder blocks loosely wrapped with geotextile fence material and arrangements of filtering rocks contained within loosely woven cloth, these latter two arrangements being commonly referred to as “pigs-in-a-blanket.” These types of filter systems, however, often tend to be either difficult to transport and deploy or, after being deployed, tend to be insufficiently stable to maintain their position in the face of rushing water, wind or other forces and do not meet current clean water regulations.
Accordingly, it can be seen that a need exists for a system for covering and protecting curb inlets of a storm water collection basin of a drainage system to prevent silt and sediment from migrating into the inlet while still allowing for the free and substantially complete drainage of storm water runoff into the curb inlet.